The movie is based on Demon Slayer: Kimetsu no Yaiba, the wildly popular anime and manga series that follows Tanjiro Kamado, a teen who turned to demon-slaying after a demon killed his entire family and turned his sister, Nezuko, into a demon. In season one, Tanjiro and a pacified Nezuko comb Japan looking for a way to turn Nezuko human again, fighting a lot of demons along the way. The movie picks up where season 1 left off and acts as a canonical bridge between season 1 and the soon-to-be-released season 2. During just its opening weekend in Japan last year, Demon Slayer: Mugen Train earned more than $350 million and beat out Spirited Away to become the highest-grossing Japanese film of all time. Mugen Train was also the fourth highest-grossing movie in 2020. If this film is anything like the series, Mugen Train will be action-packed, beautifully animated, and the characters will have bomb outfits.